Bowen ratio

Bowen Ratio is a dimensionless number used in the field of meteorology to describe the relationship between the rates of heat transfer and evaporation at the Earth's surface. Named after the Australian meteorologist I. G. Bowen, who first introduced the concept in 1926, the Bowen Ratio is a key factor in understanding the energy balance of the Earth's surface and the processes that drive weather and climate.

Definition

The Bowen Ratio (β) is defined as the ratio of sensible heat flux (H) to latent heat flux (LE). Mathematically, it can be expressed as:

β = H / LE

Where:

• H is the sensible heat flux, the energy transferred by the process of conduction and convection.
• LE is the latent heat flux, the energy associated with the phase change of water, such as evaporation or condensation.

Applications

The Bowen Ratio is used in various applications in meteorology and climatology. It is particularly useful in understanding and predicting the evapotranspiration process, which is crucial for agricultural and hydrological models. It also plays a significant role in the study of land surface processes, climate modeling, and weather forecasting.

Measurement

The Bowen Ratio can be measured directly using instruments such as the Bowen Ratio Energy Balance system. Alternatively, it can be calculated from measurements of temperature, humidity, wind speed, and solar radiation.

See also

• Energy balance (Earth's surface)
• Evapotranspiration
• Heat transfer
• Meteorology